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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        var length = 10;

        function fn() {
            return this.length + 1;
        }
        var obj = {
            length: 5,
            test1: function () {
                return fn();
            }
        };
        obj.test2 = fn;
        //下面代码输出是什么  
        console.log(obj.test1())
        console.log(fn())
        console.log(obj.test2())
        console.log(fn() === obj.test2())
    </script>
</body>

</html>